Fused thiophenes, articles, and methods thereof

ABSTRACT

Fused thiophene (FT) compounds, FT polymers, FT containing articles, and methods for making and using the FT compounds and polymers thereof of the formulas, as defined herein.

The entire disclosure of any publication, patent, or patent documentmentioned herein is incorporated by reference.

BACKGROUND

The disclosure generally relates to fused thiophene compounds, polymers,compositions, articles, and to methods for making and using thethiophene compositions.

SUMMARY

The disclosure provides fused thiophene (FT) compounds and polymers thatcan be used, for example, for electronic applications, such as lightemitting devices and semiconductor devices, and methods of making andusing the fused thiophene products.

BRIEF DESCRIPTION OF THE DRAWING(S)

FIG. 1 provides a representative current-voltage curve for a deviceprepared from polymer 10, in embodiments of the disclosure.

DETAILED DESCRIPTION

Various embodiments of the disclosure will be described in detail withreference to drawings, if any. Reference to various embodiments does notlimit the scope of the invention, which is limited only by the scope ofthe claims attached hereto. Additionally, any examples set forth in thisspecification are not limiting and merely set forth some of the manypossible embodiments for the claimed invention.

DEFINITIONS

“FTx” refers to fused thiophene where x is an integer indicating thenumber of fused thiophene ring or cycle units fused into a single coreunit, for example, a FT2 has two fused rings in the core unit, a FT3 hasthree fused rings in the core unit, a FT4 has four fused rings in thecore unit, a FT5 has five fused rings in the core unit, and like higherdesignations in the core unit.

“Unit,” “polymerizable unit,” or like terms in the context of thedisclosed fused thiophene polymers refer to the number of different coreunits and like other conjugated units within a discrete repeat segment(n) of a polymer, see for example the core fused thiophene unit, and G¹unit (note that two G¹ groups are present), and the G₂ unit in Scheme1(d). A repeat unit can have one or more like core units and one or moreadditional conjugated units within a discrete repeat segment of apolymer.

“Hydrocarbon,” “hydrocarbyl,” “hydrocarbylene,” “hydrocarbyloxy,” andlike terms refer to monovalent such as —R, or divalent —R— moieties, andcan include, for example, alkyl hydrocarbons, aromatic or arylhydrocarbons, alkyl substituted aryl hydrocarbons, alkoxy substitutedaryl hydrocarbons, heteroalkyl hydrocarbons, heteroaromatic orheteroaryl hydrocarbons, alkyl substituted heteroaryl hydrocarbons,alkoxy substituted heteroaryl hydrocarbons, and like hydrocarbonmoieties, and as illustrated herein.

“Alkyl” includes linear alkyls, branched alkyls, and cycloalkyls.“Substituted alkyl” or “optionally substituted alkyl” refers to an alkylsubstituent, which can include, for example, a linear alkyl, a branchedalkyl, or a cycloalkyl, having from 1 to 4 optional substituentsselected from, for example, hydroxyl (—OH), halogen, amino (—NH₂ or—NR₂), nitro (—NO₂), acyl (—C(═O)R), alkylsulfonyl (—S(═O)₂R), alkoxy(—OR), and like substituents, where R is a hydrocarbyl, aryl, Het, orlike moieties, such as a monovalent alkyl or a divalent alkylene havingfrom 1 to about 10 carbon atoms. For example, a hydroxy substitutedalkyl, can be a 2-hydroxy substituted propylene of the formula—CH₂—CH(OH)—CH₂—, an alkoxy substituted alkyl, can be a 2-methoxysubstituted ethyl of the formula —CH₂—CH₂—O—CH₃, an amino substitutedalkyl, can be a 1-dialkylamino substituted ethyl of the formula—CH(NR₂)—CH₃, an oligo-(oxyalkylene), poly-(oxyalkylene), orpoly-(alkylene oxide) substituted alkyl, can be, for example, of thepartial formula —(R—O)_(x)—, where x can be, for example, from 1 toabout 50, and from 1 to about 20, and like substituted oxyalkylenesubstituents, such as of the formula —(CR⁵—CHR⁵—O)_(x)— where R⁵ ishydrogen or a substituted or unsubstituted (C₁₋₈) hydrocarbyl such asalkyl, and x is an integer of from 1 to about 50.

“Aryl” includes a mono- or divalent-phenyl radical or an ortho-fusedbicyclic carbocyclic radical having about nine to twenty ring atoms inwhich at least one ring is aromatic. Aryl (Ar) can include substitutedaryls, such as a phenyl radical having from 1 to 5 substituents, forexample, alkyl, alkoxy, halo, and like substituents.

“Het” includes a four-(4), five-(5), six-(6), or seven-(7) memberedsaturated or unsaturated heterocyclic ring having 1, 2, 3, or 4heteroatoms selected from the group consisting of oxy, thio, sulfinyl,sulfonyl, selenium, tellurium, and nitrogen, which ring is optionallyfused to a benzene ring. Het also includes “heteroaryl,” whichencompasses a radical attached via a ring carbon of a monocyclicaromatic ring containing five or six ring atoms consisting of carbon and1, 2, 3, or 4 heteroatoms each selected from the group consisting ofnon-peroxide oxy, thio, and N(X) wherein X is absent or is H, O,(C₁₋₄)alkyl, phenyl, or benzyl, and a radical of an ortho-fused bicyclicheterocycle of about eight to ten ring atoms derived therefrom,particularly a benzo-derivative or one derived by fusing a propylene,trimethylene, or tetramethylene diradical thereto.

In embodiments, halo or halide includes fluoro, chloro, bromo, or iodo.Alkyl, alkoxy, etc., include both straight and branched groups; butreference to an individual radical such as “propyl” embraces only thestraight chain radical, a branched chain isomer such as “isopropyl”being specifically referred to.

The carbon atom content of various hydrocarbon-containing (i.e.,hydrocarbyl) moieties can alternatively be indicated by a prefixdesignating a lower and upper number of carbon atoms in the moiety,i.e., the prefix C_(i-j) indicates a moiety of the integer “i” to theinteger “j” carbon atoms, inclusive. Thus, for example, (C₁-C₈)alkyl orC₁₋₈alkyl refers to an alkyl of one to eight carbon atoms, inclusive,and hydrocarbyloxy such as (C₁-C₈)alkoxy or C₁₋₈alkoxy refers to analkoxy radical (—OR) having an alkyl group of one to eight carbon atoms,inclusive.

Specifically, C₁₋₈alkyl can be, for example, methyl, ethyl, propyl,isopropyl, butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, 3-pentyl,hexyl, heptyl, or octyl; (C₃₋₁₂)cycloalkyl can be cyclopropyl,cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, includingbicyclic, tricyclic, or multi-cyclic substituents, and likesubstituents.

A specific “hydrocarbyl” can be, for example, (C₁₋₂₄)hydrocarbyl,including all intermediate chain lengths and values.

C₁₋₈alkoxy can be, for example, methoxy, ethoxy, propoxy, isopropoxy,butoxy, iso-butoxy, sec-butoxy, pentoxy, 3-pentoxy, hexyloxy,1-methylhexyloxy, heptyloxy, octyloxy, and like substituents.

H—C(═O)(C₃₋₇)alkyl- or —(C₂₋₇)alkanoyl can be, for example, acetyl,propanoyl, butanoyl, pentanoyl, 4-methylpentanoyl, hexanoyl, orheptanoyl. Aryl (Ar) can be, for example, phenyl, naphthyl, anthracenyl,phenanthrenyl, fluorenyl, tetrahydronaphthyl, or indanyl. Het can be,for example, pyrrolidinyl, piperidinyl, morpholinyl, thiomorpholinyl, orheteroaryl. Heteroaryl can be, for example, furyl, imidazolyl,triazolyl, triazinyl, oxazoyl, isoxazoyl, thiazolyl, isothiazoyl,pyrazolyl, pyrrolyl, pyrazinyl, tetrazolyl, pyridyl, (or its N-oxide),thienyl, pyrimidinyl (or its N-oxide), indolyl, isoquinolyl (or itsN-oxide) or quinolyl (or its N-oxide).

A specific value for Het includes a five-(5), six-(6), or seven-(7)membered saturated or unsaturated ring containing 1, 2, 3, or 4heteroatoms, for example, non-peroxide oxy, thio, sulfinyl, sulfonyl,selenium, tellurium, and nitrogen; and a radical of an ortho-fusedbicyclic heterocycle of about eight to twelve ring atoms derivedtherefrom, particularly a benzo-derivative or one derived by fusing apropylene, trimethylene, tetramethylene, or another monocyclic Hetdiradical thereto.

Other conditions suitable for formation and modification of thecompounds, oligomers, polymers, composites or like products of thedisclosure, from a variety of starting materials or intermediates, asdisclosed and illustrated herein are available. For example, see Feiserand Feiser, “Reagents for Organic Synthesis”, Vol. 1, et seq., 1967;March, J. “Advanced Organic Chemistry,” John Wiley & Sons, 4th ed. 1992;House, H. O., “Modern Synthetic Reactions,” 2^(nd) ed., W. A. Benjamin,New York, 1972; and Larock, R. C., “Comprehensive OrganicTransformations,” 2^(nd) ed., 1999, Wiley-VCH Publishers, New York. Thestarting materials employed in the preparative methods described hereinare, for example, commercially available, have been reported in thescientific literature, or can be prepared from readily availablestarting materials using procedures known in the field. It may bedesirable to optionally use a protecting group during all or portions ofthe above described or alternative preparative procedures. Suchprotecting groups and methods for their introduction and removal areknown in the art. See Greene, T. W.; Wutz, P. G. M. “Protecting GroupsIn Organic Synthesis,” 2^(nd) ed., 1991, New York, John Wiley & Sons,Inc.

“Include,” “includes,” or like terms means encompassing but not limitedto, that is, inclusive and not exclusive.

“Monomer,” “mer,” or like terms refer to a compound that can be (or hasalready been) covalently combined or linked with other monomers of likeor different structure to form homogenous (homopolymers) or heterogenous(e.g., copolymers, terpolymers, and like heteropolymers) chains of thetarget polymer. Suitable monomers as disclosed and illustrated hereincan include, for example, low molecular weight polymerizable compounds,such as from about 50 to about 200 Daltons, and higher molecular weightcompounds, such as from about 200 to about 10,000 Daltons, includingunsaturated oligomeric or unsaturated polymeric compounds.

“About” modifying, for example, the quantity of an ingredient in acomposition, concentrations, volumes, process temperature, process time,yields, flow rates, pressures, and like values, and ranges thereof,employed in describing the embodiments of the disclosure, refers tovariation in the numerical quantity that can occur, for example: throughtypical measuring and handling procedures used for making compounds,compositions, composites, concentrates or use formulations; throughinadvertent error in these procedures; through differences in themanufacture, source, or purity of starting materials or ingredients usedto carry out the methods; and like considerations. The term “about” alsoencompasses amounts that differ due to aging of a composition orformulation with a particular initial concentration or mixture, andamounts that differ due to mixing or processing a composition orformulation with a particular initial concentration or mixture. Theclaims appended hereto include equivalents of these “about” quantities.

“Consisting essentially of” in embodiments refers, for example, to acompound, to a polymer composition, to a method of making or using thecompound, the polymer, formulation, or composition, and articles,devices, or any apparatus of the disclosure, and can include thecomponents or steps listed in the claim, plus other components or stepsthat do not materially affect the basic and novel properties of thecompositions, articles, apparatus, or methods of making and use of thedisclosure, such as particular reactants, particular additives oringredients, a particular agent, a particular surface modifier orcondition, or like structure, material, or process variable selected.Items that may materially affect the basic properties of the componentsor steps of the disclosure or that may impart undesirablecharacteristics to the present disclosure include, for example,premature polymer chain termination, excessive crosslinking, extended orunnecessary exposure of the resulting polymer to excessively hightemperatures, and like contrary steps.

The indefinite article “a” or “an” and its corresponding definitearticle “the” as used herein means at least one, or one or more, unlessspecified otherwise.

Abbreviations, which are well known to one of ordinary skill in the art,may be used (e.g., “h” or “hr” for hour or hours, “g” or “gm” forgram(s), “mL” for milliliters, and “rt” for room temperature, “nm” fornanometers, and like abbreviations).

Specific and preferred values disclosed for components, ingredients,additives, initiators, metal catalysts, cross linkers, and like aspects,and ranges thereof, are for illustration only; they do not exclude otherdefined values or other values within defined ranges. The compositionsand methods of the disclosure include those having any value or anycombination of the values, specific values, more specific values, andpreferred values described herein.

In embodiments, the disclosure provides FT compounds, FT polymercompositions, FT containing articles, and methods for making and usingthe FT compounds and the FT polymers.

In embodiments, the disclosure provides an FT compound and a method ofmaking an FT compound as defined herein.

In embodiments, the disclosure provides an FT polymer and a method ofmaking an FT polymer as defined herein.

In embodiments, the disclosure provides an FT polymeric composition andFT articles thereof prepared by any of the processes as defined herein.

In embodiments, the disclosure provides a polymer article prepared byone or more of the processes as defined herein.

In embodiments, the disclosure provides an article or deviceincorporating the polymer or polymer article as defined herein. Thedisclosed compositions, articles, and methods can be used to preparemany different electro-optical devices, for example, OLEDs, OFETs,OTFTs, and like devices as disclosed, for example, in J. Am. Chem. Soc.,2008, 130, 13202-13203.

In embodiments, the disclosure provides a compound of the formula:

where

each R is independently a carbon-carbon bond, a carbon-sulfur bond, forexample, when n is from 2 to 4, or a substituted or unsubstituted,(C₁₋₂₄)hydrocarbyl including solubility enhancing substituents, forexample, oxygen or sulfur substituted —R substituents such as —OR, —SR,polyethers, polythioethers, and like groups;

n is an integer from 2 to 4; and

each -G¹ is independently

-   -   a carbon-carbon bond or a carbon-sulfur bond, for example, when        n is from 2 to 4;    -   a monovalent, substituted or unsubstituted, aryl of the formula        —{Ar(R¹)_(q)}_(p)—Ar(R¹)_(q),    -   a monovalent, substituted or unsubstituted, heteroaryl of the        formula -{Het(R¹)_(q)}_(p)-Het(R¹)_(q), or    -   a monovalent combination of one or more, substituted or        unsubstituted, aryl and heteroaryl substituents, of the formulas        —{Ar(R¹)_(q)}_(p)-Het(R¹)_(q), or -{Het(R¹)_(q)}_(p)—Ar(R¹)_(q),        such as -Het-Ar, —Ar-Het, -Het(R¹)_(q)—Ar, —Ar-Het(R¹)_(q),        -Het(R¹)_(q)—Ar(R¹)_(q), and like combinations,

p is 0 to 4,

q is 0 to 4, and

each —R¹ is independently —H, —F, or a monovalent, substituted orunsubstituted, saturated or unsaturated, (C₁₋₂₄)hydrocarbyl, or acombination thereof, and salts thereof.

Examples of —{Ar(R¹)_(q)}_(p)—Ar(R¹)_(q) include, for example, —Ar(R¹)where p is 0 and q is 1, such as —Ar, or —Ar(R¹), —Ar(R¹)—Ar(R¹)— wherep is 1 and q is 1 and R¹ is alkyl, or —Ar—Ar—Ar, where p is 2 and q is 0and R¹ is —H and like permutations. Examples of -{Het(R¹)}_(p)-Het(R¹)include, for example, -Het, -Het-Het, -(Het)-2-Het, -Het(R¹),-Het(R¹)-Het, -Het-Het(R), -Het(R¹)-Het-(R¹), and like permutations,including, for example, phenyl, toluoyl, naphthyl, biphenyl,bithiophene, and like moieties. Examples of (C₁₋₂₄)hydrocarbyl include,for example, substituted or unsubstituted, saturated or unsaturatedhydrocarbyls, such as alkynyl, alkenyl, alkylenyl, or a combinationthereof.

-G¹ combinations can include, for example, —Ar-Het, -Het-Ar,—Ar(R¹)-Het(R¹), -Het(R¹)—Ar(R¹); and like permuations of—{Ar(R¹)_(q)}_(p)-Het(R)_(q), or -{Het(R¹)_(q)}_(p)—Ar(R¹)_(q), andsalts thereof.

Specific examples of the monovalent -G¹ moiety can be, for example, atleast one substituent selected from

or a combination thereof,

each R² is independently H, or a monovalent, substituted orunsubstituted, saturated or unsaturated, (C₁₋₂₄)hydrocarbyl, or —Ar, —F,or a combination thereof,

R³ is H, or a monovalent, substituted or unsubstituted, saturated orunsaturated, (C₁₋₂₄)hydrocarbyl, and

s is an integer from 0 to 5.

Examples of R² can be any of —(C₁₋₂₄)hydrocarbyl, —(C₁₋₁₀)alkoxyl,—{(C₁₋₁₀)alkoxyl}_(t)-H, -oxyalkylene, -(oxyhydrocarbylene)_(t)H, —Ar,and like substituents, where t is from 1 to 10.

In embodiments, the disclosure provides a compound of the formula:

including a salt thereof, or a combination thereof, or a mixturethereof.

Specific named compounds can include, for example,

-   4,11-bis(thiophen-2-yl)-5,12-ditridecyl-3,7,10,14-tetrathiatetracyclo[6.6.0.0^(2,6).0^(9,13)]tetradeca-1(8),2(6),4,9(13),    11-pentaene;-   4,11-bis(thiophen-2-yl)-5,12-diheptadecyl-3,7,10,14-tetrathiatetracyclo[6.6.0.0^(2,6).0^(9,13)]tetradeca-1(8),2(6),4,9(13),    11-pentaene;-   6,14-bis(thiophen-2-yl)-5,15-ditridecyl-3,7,10,13,17-pentathiapentacyclo[9.6.0.0^(2,9).0^(4,8).0^(12,16)]heptadeca-1(11),2(9),4(8),5,12(16),14-hexaene;-   4,11-diphenyl-5,12-ditridecyl-3,7,10,14-tetrathiatetracyclo[6.6.0.0^(2,6).0^(9,13)]tetradeca-1(8),2(6),4,9(13),    11-pentaene;-   6,14-diphenyl-5,15-ditridecyl-3,7,10,13,17-pentathiapentacyclo[9.6.0.0^(2,9).0^(4,8).0^(12,16)]heptadeca-1(11),2(9),4(8),5,12(16),14-hexaene;-   4,11-bis(4-trifluoromethylphenyl)-5,12-diheptadecyl-3,7,10,14-tetrathiatetracyclo[6.6.0.0^(2,6).0^(9,13)]tetradeca-1(8),2(6),4,9(13),11-pentaene;    or-   4,11-diphenyl-5,12-diheptadecyl-3,7,10,14-tetrathiatetracyclo[6.6.0.0^(2,6).0^(9,13)]tetradeca-1(8),2(6),4,9(13),    11-pentaene; and a salt thereof, or a mixture thereof.

In embodiments, -G¹ can be any monovalent moiety selected from, forexample,

and isomeric permutations thereof, and where the asterisk “*” in thesubstituents represents the monovalent attachment point to the fusedthiophene core.

In embodiments, the disclosure provides a method for making a fusedthiophene compound of the formula:

as defined herein, comprising:contacting a fused thiophene core compound of the formula:

with an halogenating agent to form the α-, α′-, dihalogenated product ofthe formula X—C—X where X is halogen, and C is the contacted corecompound; and

contacting the X—C—X product with at least two mole equivalent of acoupling compound of the formula M-G¹ and a metal catalyst to form theα-, α′-, disubstituted product of the formula G¹-C-G¹.

More specifically the method of making can have a coupling compound ofthe formula M-G¹ which can include, for example, an M having an —SnR⁴ ₃,—B(OH)₂, —B(OR⁴)₂, —B(cyclo-OR⁴O—), or —MgX, or a combination thereof,where X is halo, each R⁴ independently is a monovalent; substituted orunsubstituted, (C₁₋₂₄)hydrocarbyl, and

-G¹ is a monovalent moiety that can be selected from, for example,

or a combination thereof,

each R² is independently H, or a monovalent, substituted orunsubstituted, saturated or unsaturated, (C₁₋₂₄)hydrocarbyl, —Ar, —F,and like substituents as defined herein, or a combination thereof,

R³ is H, or a monovalent, substituted or unsubstituted, saturated orunsaturated, (C₁₋₂₄)hydrocarbyl, and

s is an integer from 0 to 5.

A halogenating agent can be, for example, a brominating agent such asNBS, Br₂, a chlorinating agent such as NCS, Cl₂, an iodinating agentsuch as NIS, 12, and like agents, or combinations thereof.

The metal catalyst can be, for example, Pd(PPh₃)₄, or like agents suchas based on Pt, Ni, or like metals.

In embodiments, the disclosure provides a polymer of the formula:

where

each R is independently a carbon-carbon bond, a carbon-sulfur bond, or asubstituted or unsubstituted, (C₁₋₂₄)hydrocarbyl;

n is an integer from 2 to 4;

m is an integer from 2 to 10,000, including intermediate values andranges; and

each G¹ is independently

-   -   a carbon-carbon bond or a carbon-sulfur bond,    -   a divalent, substituted or unsubstituted, aryl of the formula        —{Ar(R¹)_(q)}_(p)—Ar(R¹)_(q)—, or    -   a divalent, substituted or unsubstituted, heteroaryl of the        formula -{Het(R¹)_(q)}_(p)-Het(R¹)_(q)—,

each —R¹ is independently —H, —F, or a monovalent, substituted orunsubstituted, saturated or unsaturated, (C₁₋₂₄)hydrocarbyl, or acombination thereof, and salts thereof,

each G² is independently

-   -   a divalent, substituted or unsubstituted, aryl of the formula        —{Ar(R¹)_(q)}_(p)—Ar(R¹)_(q)—,    -   a divalent, substituted or unsubstituted, heteroaryl of the        formula -{Het(R¹)_(q)}_(p)-Het(R¹)_(q)—, or    -   a divalent, substituted or unsubstituted, unsaturated        (C₁₋₂₄)hydrocarbyl, such as a vinyl or acetylenyl,

each p is independently from 0 to 4,

each q is independently from 0 to 4, and

each —R¹ is independently —H, —F, or a monovalent, substituted orunsubstituted, saturated or unsaturated, (C₁₋₂₄)hydrocarbyl, or acombination thereof, and a salt thereof.

In embodiments, the disclosed polymers can have a molecular weight, forexample, of about 300 to about 25,000 or more.

In embodiments, the disclosure provides a method for making the polymerof the formulas:

as defined here, comprising:

contacting a core compound (C) of the formula:

with an halogenating agent to form the α-, α′-, dihalogenated product ofthe formula X-G¹-C-G¹-X where C is the contacted core compound and X ishalogen; and

contacting the X-G¹-C-G¹-X product with about one mole equivalent ratioof a coupling compound of the formula M-G²-M and a metal catalyst toform the polymer.

In the preparative method to form the polymer, M-G²-M can be, forexample, a coupling compound, for example, of the formula R⁴ ₃Sn-G²-SnR⁴₃ using Stille coupling conditions; (HO)₂B-G²-B(OH)₂,(R⁴O)₂B-G²-B(OR¹)₂, (cyclo-OR⁴O—)B-G²-B(cyclo —OR⁴O—), or like metalcoupling compounds using Suzuki coupling conditions; XMg-G²-MgX, usingGrignard coupling conditions, and like conditions, or combinationsthereof, where R⁴ can independently be a monovalent or divalent(C₁₋₈)hydrocarbyl such as alkyl, alkylene, alkyne, including branchedand cyclic hydrocarbyls such as cyclo(C₃₋₈)alkyl, or divalent(C₁₋₈)hydrocarbyls including cyclic glycol ethers, such as—B(cyclo-OR⁴O—), and like substituents, where X is halogen, and -G²- canbe a divalent moiety of the formula, for example,

or a combination thereof,

each R² is independently H, or a monovalent, substituted orunsubstituted, saturated or unsaturated, (C₁₋₂₄)hydrocarbyl, —Ar, —F,and like substituents as defined herein or a combination thereof,

R³ is H, or a monovalent, substituted or unsubstituted, saturated orunsaturated, (C₁₋₂₄)hydrocarbyl,

s is an integer from 0 to 5, and the metal catalyst is Pd(PPh₃)₄.

In embodiments the disclosure provides a method for making a polymer,comprising:

contacting a core compound of the formula:

with a halogenating agent to form the α-, α′-, dihalo product of theformula X—C—X where C is the contacted core compound and X is halo; and

contacting the X—C—X product with about one mole ratio equivalent, forexample, of from about 0.8 to about 1.2 mole ratio equivalents, of fromabout 0.9 to about 1.1 mole ratio equivalents, and preferably of fromabout 1.0 mole ratio equivalent, that is a 1:1 molar or mole ratioequivalents, of a coupling compound of the formula M-G¹-G²-G¹-M, and ametal catalyst to form the respective polymer products of the formulas:

where each R is independently a monovalent, substituted orunsubstituted, (C₁₋₂₄)hydrocarbyl, n is an integer from 2 to 4, and m isan integer from 2 to 10,000.

In embodiments, the coupling compound M-G₁-G²-G¹-M comprises: an Mhaving at least one —SnR⁴ ₃, —B(OH)₂, —B(OR⁴)₂, —B(cyclo-OR⁴O—), or—MgX, or a combination thereof, and each R⁴ of the coupling compound canindependently be a monovalent, substituted or unsubstituted,(C₁₋₂₄)hydrocarbyl, and

each G¹ and G² is independently a divalent moiety selected, for example,from

or a combination thereof,

each R² is independently H, or a monovalent, substituted orunsubstituted, saturated or unsaturated, (C₁₋₂₄)hydrocarbyl, —Ar, —F,and like substituents as defined herein or a combination thereof,

R³ is H, or a monovalent, substituted or unsubstituted, saturated orunsaturated, (C₁₋₂₄)hydrocarbyl,

s is an integer from 0 to 5, and the metal catalyst is Pd(PPh₃)₄.

In embodiments, the dihalogenated compound can be, for example, of theformulaX-G¹-C-G¹-Xwhere

C is a divalent fused thiophene core of the formula:

each -G¹- is independently:

-   -   a divalent, substituted or unsubstituted, aryl of the formula        —{Ar(R¹)_(q)}_(p)—Ar(R¹)_(q)—, or    -   a divalent, substituted or unsubstituted, heteroaryl of the        formula -{Het(R¹)_(q)}_(p)-Het(R¹)_(q)—,

each —R¹ is independently —H, —F, or a monovalent, substituted orunsubstituted, saturated or unsaturated, (C₁₋₂₄)hydrocarbyl, or acombination thereof, and salts thereof,

each p is independently from 0 to 4,

each q is independently from 0 to 4, and

each X is independently halo, or a salt thereof, or mixtures thereof.

Specific dihalogenated compounds of the formula X-G¹-C-G¹-X can be, forexample, of the formulas (7) and (9):

having the corresponding chemical name of:

-   4,11-bis(5-bromothiophen-2-yl)-5,12-ditridecyl-3,7,10,14-tetrathiatetracyclo[6.6.0.0^(2,6).0^(9,13)]tetradeca-1(8),2(6),4,9(13),11-pentaene    (7); and-   6,14-bis(5bromothiophen-2-yl)-5,15-ditridecyl-3,7,10,13,17-pentathiapentacyclo[9.6.0.0^(2,9).0^(4,8).0^(12,16)]heptadeca-1(11),2(9),4(8),5,12(16),14-hexaene    (9).

He, M., et al., have previously reported several synthetic methods formaking β-, β′-alkyl substituted fused thiophenes from FT2 to FT7 (seeHe, M., Int. Appl. PCT/US08/02033, PCT Publication No. WO08/106,019,U.S. Pat. Appl. Publ. US-2007-0161776 A1, a cont.-in-part of Appln. No.PCT/US2005/032759, entitled “Fused Thiophenes, Methods for Making FusedThiophenes, and Uses Thereof”; He, M., et al., J. Org. Chem. (2007),72(2), 442-451, Synthesis and Structure of Alkyl-Substituted FusedThiophenes Containing up to Seven Rings; and commonly owned and assignedPCT Int. Appl. PCT/US05/32759, PCT Pub. No. WO06/031893, entitled“Preparation of Fused Thiophenes”).

Related α-, α′-, β-, β′-unsubstituted fused thiophenes have beenreported elsewhere (see for example, Fong, H. et al., J. Am. Chem. Soc.,(2008), 130(40), 13202-13203, Tetrathienoacene Copolymers As HighMobility, Soluble Organic Semiconductors; Zhang, X., et al., J. Am.Chem. Soc. (2005), 127(30), 10502-10503, Synthesis and Structure ofFused-Oligothiophenes with up to Seven Rings; Okamoto, T., et al.,Chemistry—A European Journal (2007), 13(2), 548-556, General Synthesisof Extended Fused Oligo-Thiophenes Consisting of an Even Number ofThiophene Rings).

In embodiments, the disclosure provides α-, α′-substituted, β-, β′-alkylsubstituted fused thiophene compounds (e.g., FT4, FT5, FT6, FT7, FT8,and FT9) and methods for making the compounds. Several of the β-,β′-alkyl substituted fused thiophene compounds, such as those having α-,α′-conjugated functional group substituents, can be used as organicsemiconductors in electronic devices.

In embodiments, the disclosure also provides fused thiophene corecompounds and their corresponding polymers having one or more additionalmer units included or appended to the core. In embodiments, theadditional appended unit or units can participate in polymerization andchain extension. The resulting product can be a polymer having a repeatsegment (n) including, for example, at least one core unit (C) havingfour or more fused thiophene rings, at least one G¹ unit, and at leastone G² unit.

In embodiments, the resulting product can be a polymer having a repeatsegment including, for example, a single fused thiophene core unit, atleast two G¹ units, and a single G² unit. In embodiments, the disclosureprovides a method for preparing polymers and block copolymers havingchain segments containing, for example, from about 4 to about 10 fusedthiophene units. In embodiments, the disclosure provides a method forpreparing fused thiophene containing polymers and block copolymersusing, for example, Stille or Suzuki coupling reactions.

In embodiments, the disclosure provides β-, β′-alkyl substituted fusedthiophenes that have improved solubility in common organic solventscompared to previously reported α-, α′-, β-, β′-unsubstituted fusedthiophenes. The excellent solubility property makes these materials andtheir conjugated polymer products suitable for solution processedorganic electronics, particularly for printing applications (see PCTAppl. (not yet filed), USSN provisional patent application No.61/072,468, assigned to Corning, Inc., filed Mar. 31, 2008, entitled“Fused Thiophenes and Methods for Making and Using Same”; Fong, H. etal., Tetrathienoacene Copolymers As High Mobility, Soluble OrganicSemiconductors, J. Am. Chem. Soc., (2008), 130(40), 13202-13203). Thedisclosed thiophenes also exhibit excellent thermal stability and airstability compared to, for example, pentacene, which rapidly decomposesin solution and in the presence of air. There have been reports ofthiophene, phenyl, or other conjugated functional group substitutedanthracene, tetracene, and pentacenes, that show good electronicproperties (see Anthony, J. E., Chemical Reviews (2006), 106(12),5028-5048, Functionalized Acenes and Heteroacenes for OrganicElectronics; Anthony, J. E., Angewandte Chemie, Int. Ed., (2008), 47(3),452-483, The Larger Acenes: Versatile Organic Semiconductors; Hong M.,et al., J. Am. Chem. Soc., (2006), 128(29), 9304-9305,2,6-Bis[2-(4-pentylphenyl)vinyl]anthracene: A Stable and High ChargeMobility Organic Semiconductor with Densely Packed Crystal Structure;Klauk, H., et al., Advanced Materials, (2007), 19(22), 3882-3887,Organic Transistors Based on Di(phenylvinyl)anthracene: Performance andStability; Hong M., et al., J. Am. Chem. Soc., (2005), 127(8),2406-2407, High-Performance, Stable Organic Thin-Film Field-EffectTransistors Based on Bis-5′-alkylthiophen-2′-yl-2,6-anthraceneSemiconductors). For example, single crystals of5,6,11,12-tetraphenyltetracene show a much higher mobility than those oftetracene and pentacene (Anthony, J. E., Angewandte Chemie, Int. Ed.,(2008), supra). However, the synthesis of these conjugated smallmolecules is not simple. The addition of these conjugated substituentsonto structures, which already have some degree of electronic activity,has generally resulted in a further enhancement of the electronicactivity.

Several examples of α-, α′-substituted FT3 have been reported forpotential applications as organic light-emitting transistors (OLETs)(see for example, Cicoira, F., et al., Advanced Materials, (2006),18(2), 169-174, Organic Light-Emitting Transistors Based onSolution-Cast and Vacuum-Sublimed Films of a Rigid Core ThiopheneOligomer; Sun, Y., et al., Advanced Functional Materials (2006), 16(3),426-432, High-Performance and Stable Organic Thin-Film Transistors Basedon Fused Thiophenes), Monochromatic OLED Pixel Arrays (Viola, I., etal., Advanced Materials, (2007), 19(12), 1597-1602, Bicolor Pixels froma Single Active Molecular Material by Surface-Tension-DrivenDeposition), and OTFTs (see for example, Holmes, A. B., et al., assignedto Cambridge Display Technology, Ltd., UK, WO 9912989 A1, FusedThiophenes for Electronic Devices; Farrand, L. et al., EP 1275651 A2,Preparation of Thienothiophene Analogs for use as Semiconductors orCharge Transport Materials; Sun, Y., et al., Applied Physics Letters,(2006), 88(24), 242113/1-3, Organic Thin-Film Transistors with HighMobilities and Low Operating Voltages Based on5,5′-Bis-biphenyl-dithieno[3,2-b:2′,3′-d]thiophene Semiconductor andPolymer Gate Dielectric; Melucci, M. et al., Chemistry—A EuropeanJournal, (2007), 13(36), 10046-10054, Liquid-Crystalline Rigid-CoreSemiconductor Oligothiophenes: Influence of Molecular Structure on PhaseBehaviour and Thin-Film Properties). Surprisingly, examples ofα-,β-substituted FT4, FT5, or FT6 compounds have not been reported. Thismay be attributable to the poor solubility of α-,β-unsubstituted FT4,FT5, and FT6 compounds which could make further structural modificationdifficult.

In embodiments, the disclosure provides a method for making a variety ofα-, α′-substituted, β-, β′-alkyl substituted FT4 to FT7 compoundsincluding α-, α′-conjugated functional group substituted, β-, β′-alkylsubstituted FT4 to FT7 compounds. The new compounds can have applicationin, for example, organic electronics and like applications. Inembodiments, the method includes using Stille Coupling or SuzukiCoupling for preparing three monomer unit, or higher unit polymers,containing an α-, α′-linked, β-, β′-substituted fused thiophene moietycore ranging from FT4 to FT7.

In embodiments, the compounds of the disclosure provide advantages,including for example:

the simplicity or ease with which one can synthetically manipulate orsystematically change one or more of the mers or units in the polymer toproduce new polymer structures having highly regular or repeatstructure;

the disclosed polymer preparative methods provide additional flexibilityor capability to specify the regio-regularity of the polymer structures;and

the disclosed methods can be used to make known polymers (see forexample commonly owned and assigned copending application U.S. Ser. No.61/072,468,) more efficiently, such as with fewer steps and fewerreagents.

Based upon other known and related compounds and polymers, the disclosedcompounds and polymers are expected to have excellent organicsemiconductor properties, such as increased thermal stability and oxygenstability, and increased ease of manufacture because of increasedsolubility and increased synthetic efficiency, such as fewer steps.

The disclosed compounds can be prepared using established syntheticmethods, for example, Stille Coupling, Suzuki Coupling, or a GrignardCoupling. Use of Suzuki Coupling to synthesize three-unit (fusedthiophene units) or higher unit polymers containing an α-, α′-coupled,β-, β′-substituted fused thiophene is not believed to have beenpreviously reported. The disclosed preparative methods can be used toprepare known fused thiophene polymers (see for example, Pan, H., etal., J. Am. Chem. Soc., (2007), 129(14), 4112-4113, Low-Temperature,Solution-Processed, High-Mobility Polymer Semiconductors for Thin-FilmTransistors), using for example, FeCl₃ oxidization.

In general, the disclosed methods provide improved preparation ofsemi-conducting polymers containing more than one mer or unit (i.e.,conjugated unit). While some of the disclosed compounds have beenpreviously prepared by co-polymerization, such as the above mentionedG¹-C-G¹ based copolymers, the disclosed methods provide a moreconvergent route to prepare the compounds using a reduced number ofco-monomers, for example, where multiple units are included in a singlemer or polymerizable unit. This provides more structurally uniformpolymers which can provide better structural organization in electronicdevices and improved electronic properties.

In embodiments, the disclosure provides improved solubility of themonomers and three-unit (or higher unit) polymers containing an α-,α′-coupled, β-, β′-substituted fused thiophene because a side-chainmodification can be accomplished on any of the monomers or three-unitpolymers.

In embodiments, the disclosure provides a method of making α-,α′-coupled, β-, β′-substituted fused thiophenes, including α-,α′-aromatic ring substituted, β-, β′-alkyl substituted FT4 to FT7compounds. The general Schemes 1(a-d) illustrated below for preparingα-, α′-substituted, β-, β′-alkyl substituted FT4 and FT5 compounds areapplicable to FT6, FT7, and FT8 compounds, and like compounds.

Scheme 1 (a) Synthesis of α-, α′-substituted, β-, β′-alkyl substitutedFT4.

where M-G¹ can be, for example,

Scheme 1(b) Synthesis of α-, α′-substituted, β-, β′-alkyl substitutedFT5.

Scheme 1(c) Exemplary synthesis of three-unit polymers from α-,α′-aromatic ring substituted, β-, β′-alkyl substituted fused thiophenesFT4 and FT5.

where M-G²-M is as defined herein.Scheme 1(d) Alternative exemplary syntheses of a three-unit polymer.

where M-G¹-G²-G¹-M is as defined herein.

The syntheses of thiophene substituted FT4 (3) and FT5 (6) compounds areshown in accompanying Schemes 2(a) and 2(b), respectively. Thepreparative procedure begins with a dibromination reaction in the α,α′-positions of the α-, α′-unsubstituted, β-, β′-alkyl substituted fusedthiophene. This can be accomplished, for example, withN-bromosuccinimide (NBS), or other like brominating agents. Theresulting dibromo-FT derivatives can then be reacted with an appropriatetin reagent, for example, 2-tributyltin thiophene, and a catalyst. Avariety of reagents, as shown in Scheme 1(a), can be used. While a tinreagent based Stille Coupling was demonstrated in the synthesis of thesematerials, other known methods to form the C—C bond, such as SuzukiCoupling, as shown in Scheme 2(c), and Grignard coupling, can be used toobtain the new compounds.

Scheme 2(a) Synthesis of α-, α′-thiophene substituted, β-, β′-alkylsubstituted FT4 using Stille coupling.

Scheme 2(b) Synthesis of α-, α′-thiophene substituted, β-, β′-alkylsubstituted FT5 using Stille Coupling.

Scheme 2(c) Synthesis of α-, α′-p-trifluoromethylphenyl substituted, β-,β′-alkyl substituted FT5 using Suzuki coupling.

Specific examples of methods to prepare polymers based on the newcompounds 3 and 6 are shown in Scheme 2(d). The first step can be, forexample, bromination of compound 3 or compound 6 with NBS, or likeagents, and combinations thereof. The brominated compounds 7 and 9 canthen be reacted with a di-tin aryl or like derivative, such as1,4-bis-trimethyltin benzene as shown, in the presence of a metalcatalyst to form the polymers 8 and 10. In general, any aryl di-tin,vinyl di-tin, or acetylenic di-tin compound can be selected for use inthe reaction to make the corresponding polymers. While the tin basedStille coupling polymerization was specifically demonstrated, otherknown metal catalyzed processes for the co-polymerization of aryl,vinyl, and acetylenic units via C—C bond formation, such as the Suzukicoupling shown in Scheme 2(c), or Grignard coupling can be used to forma variety of polymeric structures. The choice of coupling chemistryselected for a specific polymerization can be suggested or dictated bythe type or types of monomers being polymerized.

Scheme 2(d) synthesis of three-unit polymers containing α-, α′-thiophenesubstituted, β-, β′-alkyl substituted FT4 and FT5.

The monomer compounds of the disclosure in combination with variouspolymerization chemistries can provide great structural flexibility andaccess to numerous multi-unit polymers, for example, as illustrated inSchemes 1(c) and 1(d). The polymers shown in Scheme 1(c) consist ofco-polymers made from two monomers. However, these polymers areconsidered to be three unit polymers having the added units G¹ and G² tothe starting FT core, where G¹ and G² can be, for example, aryl, vinyl,acetylenic, or like groups. As shown in Scheme 1(d), the flexibility ofthe polymerization process allows for the formation of the same polymersshown in Scheme 1(c) by a different route. This alternative approach maybe advantageous where a particular monomer unit is difficult to prepareor otherwise difficult to obtain. The ability of coupling chemistry toselectively place a unit in a particular position in the repeatedsequence can provide polymers having more uniform two-dimensionalstructures compared to forming these polymers in randomco-polymerization reactions. Although not limited by theory, thesematerials can pack more uniformly when they are assembled intoelectronic devices, and their semi-conducting properties can be enhancedcompared to the more random polymer structures. We have unexpectedlydiscovered that certain fused thiophene compounds of the disclosure, andrelated compounds, can have superior, i.e., more compact, crystallinepacking properties and the corresponding polymers can have superiorconducting mobilities, when the compound has a C₂ symmetry element,where the C₂ symmetry element, or 180° rotational axis, is perpendicularto the plane of the fused thiophene core. In embodiments, the structureof the fused thiophene compounds having superior properties includethose fused thiophenes of the formula FTx where x is even and the C₂symmetry is about a rotational axis that is perpendicular to the planeof the fused thiophene core. Compounds and polymers of the disclosurehaving superior conducting mobility include FTx structures where x is aneven integer of fused thiophene rings, such as FT4, FT6, FT8, and likestructures compared to, for example, FTx structures where x is an oddinteger of fused thiophene rings, such as FT5, FT7, FT9, and likestructures.

The hole conducting mobility of polymer 8 shown in Scheme 2(d) wasmeasured as described in the experimental section. A mobility of about0.005 to about 0.01 cm²V⁻¹s⁻¹ was measured and I_(on/off) ratio of 10⁵was obtained.

EXAMPLES

The following examples serve to more fully describe the manner of usingthe above-described disclosure, and the best modes contemplated forcarrying out various aspects of the disclosure. It is understood thatthese examples do not limit the scope of this disclosure, but rather arepresented for illustrative purposes.

Example 1 Synthesis of α-, α′-Thiophene Substituted, β-, β′-AlkylSubstituted Fused Thiophene FT4(3)

Compound 2 (di-C13-FT4 di-bromide) was synthesized according to J. Amer.Chem. Soc., 2008, 130, 13202-13203. To 0.58 g of compound 2 (0.75 mmol)in a microwave reaction test tube fitted with a stir bar, 0.62 g (1.65mmol) of 2-thioenyl tri-n-butyltin, i.e., M-G¹, was added. This tube wasflushed through by nitrogen for several minutes, sealed, and place in aglovebox. 0.250 g (0.216 mmol) of Pd(PPh₃)₄ and 9 mL of toluene wereadded to the tube. This tube was again sealed and placed into themicrowave reactor. After 40 minutes at 120° C. in the reactor, thereaction mixture was purified by short-path silica gel columnchromatography, using hot hexane as the elutant. Under reduced pressure,the hexane solvent was removed to yield an oily product to which about100 mL of a methanol/ethanol (1:1) (v:v) mixture was added to yield 3 asa yellow precipitate. The precipitate was collected by filtration anddried under vacuum (0.49 g, 84% yield). ¹H NMR (300 MHz, CD₂Cl₂): δ 7.40(d, J=5.1 Hz, 2H), 7.22 (d, J=3.3 Hz, 2H), 7.12 (br t, J=4.5 Hz, 2H),2.93 (t, J=7.8 Hz, 4H), 1.79 (p, J=7.5 Hz, 4H), 1.51-1.17 (m, 40H), 0.87(t, J=6.6 Hz, 6H); HRMS (MALDI) m/z calcd for [C₄₄H₆₀S₆] 780.2967, found780.30193.

Synthesis of α-, α′-Thiophene Substituted, β-, β′-Alkyl SubstitutedFused Thiophenes FT5 (6).

Compound 5 (di-C13-FT5 di-bromide) was synthesized according to J. Amer.Chem. Soc., 2008, 130, 13202-13203. To 0.99 g of compound 5 (1.19 mmol)in a microwave reaction test tube fitted with a stir bar, 0.93 g (2.50mmol) of 2-thioenyl tri-n-butyltin was added. This tube was flushed withnitrogen for several minutes, sealed, and placed into a glove box. 0.413g (0.357 mmol) of Pd(PPh₃)₄ and 12 mL of toluene were added to the tube.This tube was again sealed and placed into a microwave reactor. After 40minutes at 120° C. in the reactor, the reaction mixture was purified byshort-path silica gel column chromatography, using hexane as theelutant. Under reduced pressure, the hexane solvent was removed to yieldan oily product to which about 100 mL of a methanol/ethanol (1:1)mixture was added to yield 6 as a yellow precipitate. The yellowprecipitate was collected by filtration and dried under vacuum (0.91 g,91% yield). ¹H NMR (300 MHz, CD₂Cl₂): δ 7.41 (d, J=4.2 Hz, 2H), 7.22 (d,J=3.6 Hz, 2H), 7.12 (br t, J=4.0 Hz, 2 H), 2.94 (t, J=7.8 Hz, 4H), 1.79(p, J=7.5 Hz, 4H), 1.52-1.18 (m, 40H), 0.87 (t, J=6.6 Hz, 6H); HRMS(MALDI) m/z calcd for [C₄₆H₆₀S₇] 836.2711, found 836.274.

Example 2 Synthesis of Three-Unit Polymer 8 from of α-, α′-ThiopheneSubstituted, β-, β′-Alkyl Substituted Fused Thiophene FT4 (7)

To a stirred solution of compound 3 (0.44 g, 0.56 mmol) in methylenechloride (30 mL) in a flask was added dropwise, a solution of N-bromosuccinimide (NBS) (0.21 g, 1.17 mmol) in DMF (15 mL). The resultingmixture was stirred in darkness for 48 hrs. Methylene chloride wasremoved with a rotary evaporator. The solid residue was washed withwater (3×100 mL) and methanol (50 mL). Solid was then dried andre-crystallized from hexane to give 0.33 grams of compound 7 (62%yield). ¹H NMR (300 MHz, CD₂Cl₂): δ 7.07 (d, J=3.6 Hz, 2H), 6.95 (d,J=3.3 Hz, 2H), 2.89 (t, J=4.5 Hz, 4H), 1.77 (p, J=6.9 Hz, 4H), 1.51-1.18(m, 40H), 0.87 (t, J=6.8 Hz, 6H); HRMS (MALDI) m/z calcd for[C₄₄H₅₈Br₂S₆] 936.1259, found 936.1230.

Three-unit polymer 8 containing α-, α′-thiophene substituted, β-,β′-alkyl substituted FT4. Compound 7 (0.32 g, 0.34 mmol) and1,4-phenylenebis (trimethylstannane) (0.14 g, 0.34 mmol), i.e. M-G′-M,were transferred into a three neck flask fitted with a stir bar.Nitrogen was passed through the flask for five minutes. The flask wassealed and placed in a glove box. To the flask were added 0.040 g(0.0341 mmol) of Pd(PPh₃)₄ and 25 mL of toluene. This flask was heatedto 120-130° C. under nitrogen for 16 hrs before being poured into amixture of methanol (200 mL) and concentrated hydrochloric acid (5 mL)solution and then stirred for 16 hrs at ambient temperature. Theresulting precipitate was filtered and extracted in a Soxhlet apparatusfor 24 h with acetone and for 24 h with hexane. The obtained polymer wasthen dissolved into 1,2-chlorobenzene and filtered, and thenprecipitated in methanol. The collected polymer product 8 was dried invacuum to 0.13 grams (45% yield). GPC (1,2-dichlorobenzene, polystyrenestandards) M_(n) 14,418, M_(w) 20,856.

Synthesis of three-unit polymer 10 from of α-, α′-thiophene substituted,β-, β′-alkyl substituted fused thiophene FT5 (9)

To a stirred solution of compound 6 (0.52 g, 0.62 mmol) in methylenechloride (130 mL) in a flask, was added dropwise a solution of N-bromosuccinimide (NBS) (0.23 g, 1.30 mmol) in DMF (60 mL). The resultingmixture was stirred in darkness for 48 hrs.

Methylene chloride was then removed with a rotary evaporator. Theremaining solid residue was washed serially with water (3×100 mL),methanol (50 mL), and ethanol (50 mL). This solid was re-crystallizedfrom hexane to give 0.58 grams of compound 9 (94% yield). ¹H NMR (300MHz, CD₂Cl₂): δ 7.09 (d, J=3.9 Hz, 2H), 6.95 (d, J=3.9 Hz, 2H), 2.90 (t,J=7.8 Hz, 4H), 1.78 (p, J=7.5 Hz, 4H), 1.52-1.18 (m, 40 H), 0.87 (t,J=6.9 Hz, 6H); HRMS (MALDI) m/z calcd for [C₄₆H₅₈Br₂S₇] 992.1007, found992.095.

Three-unit polymer 10 containing α-, α′-thiophene substituted, β-,β′-alkyl substituted thiophene FT5. Compound 9 (0.58 g, 0.58 mmol) and1,4-phenylenebis(trimethylstannane) (0.24 g, 0.58 mmol) were placed in athree neck flask fitted with a stir bar. Nitrogen was passed through theflask for five minutes. The flask was sealed and was placed in a glovebox. To the flask were added 0.067 g (0.058 mmol) of Pd(PPh₃)₄ and 25 mLof toluene. The flask was heated to 120-130° C. under nitrogen for 16hrs and then poured into a mixture of methanol (400 mL) and concentratedhydrochloric acid (5 mL) and stirred 16 hrs at ambient temperature. Theprecipitate was filtered and extracted in a Soxhlet apparatus for 24 hrswith acetone and then for 24 hrs with hexane. The remaining solid wasthen dissolved into 1,2-chlorobenzene, filtered, and precipitated inmethanol. The collected polymer was dried in vacuum to 0.47 grams (88%yield). GPC (1,2-dichlorobenzene, polystyrene standards) M_(n) 8,759,M_(w) 10,792.

Example 3 Synthesis of α-, α′-Trifluoromethylphenyl Substituted, β-,β′-Alkyl Substituted Fused Thiophenes FT4 (13)

Compound 12 was synthesized according to J. Amer. Chem. Soc., 2008, 130,13202-13203. To 0.69 g of compound 12 (0.78 mmol) in a microwavereaction test tube fitted with a stir bar, 0.37 g (1.95 mmol) of4-(trifluoromethyl)phenylboronic acid was added. To this mixture, 6 mLof 20% aqueous Na₂CO₃ and 15 mL of THF were added. This tube was flushedwith nitrogen for several minutes, sealed, and placed into a glove box.To the tube were added 0.135 g (0.117 mmol) of Pd(PPh₃)₄ and 2 mL oftoluene. This tube was again sealed and placed into the microwavereactor. After 40 minutes at 90° C. in the reactor, the organic layerwas purified by short-path silica gel column chromatography, usinghexane as the elutant. Under reduced pressure, the hexane solvent wasremoved from the elutant to yield an oily product to which about 100 mLof a methanol/ethanol (1:1) mixture was added to yield 13 as a yellowprecipitate. The yellow precipitate was collected by filtration anddried under vacuum (0.57 g, 72% yield). ¹H NMR (300 MHz, CD₂Cl₂): δ 7.70(AA′BB′, 8H), 2.86 (t, J=4.5 Hz, 4H), 1.79 (p, J=4.9 Hz, 4H), 1.54-1.19(m, 56H), 0.87 (t, J=4.7 Hz, 6H).

Example 4

Device fabrication and characterization All top-contact bottom-gatetransistors using polymer 10 as an organic semiconducting channel werefabricated in air. Si<100> wafers were used as gate electrodes withsilicon dioxide as the gate dielectric. OFET devices based on 10 in1,2-dichlorobenzene were fabricated on the octyltrichlorosilane (C8OTS)vapor treated Si/SiO₂ wafers. A general procedure for preparing OFETdevices and methods for measuring, for example, mobility are disclosed,for example, in J. Amer. Chem. Soc., 2008, 130, 13202-13203. Arepresentative current-voltage curve for the device of polymer 10 isshown in FIG. 1.

Example 5

Solubility of Selected FT4 And FT5 Compounds Table 1 provides asolubility comparison of some α-, α′-unsubstituted, β-, β′-alkylsubstituted FT4 (and FT5), with some α-, α′-substituted, β-, β′-alkylsubstituted FT4 (and FT5) compounds. General Procedure: 10 mg of a FT4or FT5 compound was mixed with 5.0 mL of a specified solvent and thensealed in a screw-top glass vial. The resulting mixture was kept in anultrasonic bath for 30 minutes at ambient temperature and then keptquiescent for 30 minutes to check whether a clear solution formed. Ifthe mixture was still not clear after these 60 minutes, an additional5.0 mL of the same solvent was added to the vial and the 60 minutemixing and standing procedure was repeated up to a total of 20 mL ofsolvent.

These results suggest a general solubility trend of these FT4 and FT5compounds. FT4 and FT5 compounds have a solubility trend of:toluene>CH₂Cl₂>hexane. α-, α′-substituted, DC13 (R═C₁₃H₃₇) FT4 compoundshave better solubility than related α-, α′-substituted, DC17 (R═C₁₇H₃₅)FT4 compounds. In general, with the same alkyl side chain, the α-,α′-phenyl, β-, β-alkyl substituted FT4 (and FT5) compounds have bettersolubility than α-, α′-thiophene, β-, β′-alkyl substituted FT4 (and FT5)compounds. The α-, α′-thiophene, β-, β′-alkyl substituted FT4 (and FT5)compounds have a slightly improved solubility over the α-,α′-unsubstituted parent β-, β′-alkyl substituted FT4 and FT5 compounds.With the same side chain, α-, α′-substituted, β-, β′-alkyl substitutedFT5 compounds have much better solubility than the related α-,α′-substituted, β-, β′-alkyl substituted FT4 compounds.

The disclosure has been described with reference to various specificembodiments and techniques. However, it should be understood that manyvariations and modifications are possible while remaining within thespirit and scope of the disclosure.

TABLE 1 Solubility of Selected FT4 and FT5 Compounds. Solvent Volume FTStructure (mL) hexane toluene CH₂Cl₂

 5 10 15 20 − − 0 0 + ++ 0 ++

 5 10 15 20 − − 0 0 ++ ++

 5 10 15 20 − 0 0 ++ ++ 0 ++

 5 10 15 20 − − − − 0 0 0 + − − − 0

 5 10 15 20 − − 0 0 0 + ++ ++ 0 + + ++

 5 10 15 20 − − − 0 ++ ++ 0 + ++

 5 10 15 20 0 ++ ++ + ++

 5 10 15 20 − − 0 0 ++ ++

 5 10 15 20 ++ ++ ++ Key: − = insoluble 0 = partially soluble + = nearlyall soluble; some minor residual ++ = complete solubility open box =presumed solubility at lower concentrations

1. A fused thiophene compound of the formula:

where each R is independently a substituted or unsubstituted,(C₁₋₂₄)hydrocarbyl; n is an integer from 2 to 4; and a salt thereof,wherein each -G¹ is independently a monovalent moiety selected from

or a combination thereof, each R² is independently H, or a monovalent,substituted or unsubstituted, saturated or unsaturated,(C₁₋₂₄)hydrocarbyl, —Ar, —F, or a combination thereof, s is an integerfrom 0 to
 5. 2. A compound of the formula

where each Ph is phenyl (—C₆H₅), each R is independently a substitutedor unsubstituted, (C₁₋₂₄)hydrocarbyl, and a salt thereof, or a mixturethereof.
 3. The compound of claim 2, selected from4,11-bis(thiophen-2-yl)-5,12-ditridecyl-3,7,10,14-tetrathiatetracyclo[6.6.0.0^(2,6).0^(9,13)]tetradeca-1(8),2(6),4,9(13),11-pentaene;4,11-bis(thiophen-2-yl)-5,12-diheptadecyl-3,7,10,14-tetrathiatetracyclo[6.6.0.0^(2,6).0^(9,13)]tetradeca-1(8),2(6),4,9(13),11-pentaene;6,14-bis(thiophen-2-yl)-5,15-ditridecyl-3,7,10,13,17-pentathiapentacyclo[9.6.0.0^(2,9).0^(4,8).0^(12,16)]heptadeca-1(11),2(9),4(8),5,12(16),14-hexaene;4,11-diphenyl-5,12-ditridecyl-3,7,10,14-tetrathiatetracyclo[6.6.0.0^(2,6).0^(9,13)]tetradeca-1(8),2(6),4,9(13),11-pentaene;6,14-diphenyl-5,15-ditridecyl-3,7,10,13,17-pentathiapentacyclo[9.6.0.0^(2,9).0^(4,8).0^(12,16)]heptadeca-1(11),2(9),4(8),5,12(16),14-hexaene;4,11-bis(4-trifluoromethylphenyl)-5,12-diheptadecyl-3,7,10,14-tetrathiatetracyclo[6.6.0.0^(2,6).0^(9,13)]tetradeca-1(8),2(6),4,9(13),11-pentaene;or4,11-diphenyl-5,12-diheptadecyl-3,7,10,14-tetrathiatetracyclo[6.6.0.0^(2,6).0^(9,13)]tetradeca-1(8),2(6),4,9(13),11-pentaene;and a salt thereof, or a mixture thereof.
 4. A method for making acompound of claim 1 of the formula:

comprising: contacting a core compound of the formula:

with an halogenating agent to form the α-, α′-, dihalogenated product ofthe formula X—C—X where X is halogen, and C is the contacted corecompound; and contacting the X—C—X product with at least two mole ratioequivalents of a coupling compound of the formula M-G¹ and a metalcatalyst to form the α-, α′-, disubstituted product of the formulaG¹-C-G¹.
 5. The method of claim 4 wherein the coupling compound of theformula M-G¹ comprises an M having an —SnR⁴ ₃, —B(OH)₂, —B(OR⁴)₂,—B(cyclo-OR⁴O—), or —MgX, or a combination thereof, where X is halogen,each R⁴ is independently a monovalent, substituted or unsubstituted,(C₁₋₂₄)hydrocarbyl, and -G¹ is a monovalent moiety selected from

or a combination thereof, each R² is independently H, or a monovalent,substituted or unsubstituted, saturated or unsaturated,(C₁₋₂₄)hydrocarbyl, —Ar, —F, or a combination thereof, R³ is H, or amonovalent, substituted or unsubstituted, saturated or unsaturated,(C₁₋₂₄)hydrocarbyl, and s is an integer from 0 to
 5. 6. The compound ofclaim 3 wherein the solubility in an organic solvent is from about 1 toabout 100 mg per milliliters.
 7. The compound of claim 3 wherein thesolubility in an organic solvent is from about 1 to about 10 mg permilliliters.
 8. The compound of claim 6 wherein the organic solvent istoluene, methylene chloride, hexane, or a mixture thereof.